1. Field of the Invention
This invention relates to a current divider for a measuring transducer. More particularly, this invention relates to the potential free measurement of currents, wherein the current to be measured is divided by means of a current divider into a measuring current and a shunt current and only the current flowing through the measuring current path is evaluated in the actual measuring transducer.
2. Description of the Prior Art
Such current dividers are described in the German Pat. No. 30 08 308 which corresponds to Great Britain Pat. No. 2,050,070 B. The current to be measured is divided into a measuring current and a shunt current by means of a current conductor which divides into two current paths in the direction of the current flow. Only the current which flows through the measuring path of the measuring transducer is utilized. The shunt path as well as the measuring path are arranged in space so far from one another that in operation they are differently heated or cooled. Consequently, no isothermic conditions exist for suppressing the measuring error due to thermal influence, such error is known to increase with the rise of current to be measured.
From U.S. Pat. No. 4,240,059, a current divider is known having two semicircular main current paths which form a circular conducting path and are connected by a measuring current path. The contact points of the measuring current path with the main current paths show slightly different potentials, so that a predetermined portion of the total current to be measured flows through the measuring current path. By changing the position of the measuring current path, the partial current which depends on the difference in potential, may be varied. Here again the isothermic conditions do not exist due to poor coupling of the individual portions of the measuring path. In addition, such solutions require compensated measuring transducers due to the small resistance of the measuring current path.
Reference is made to the U.S. patent application Ser. No. 509,447, of Richard Friedl, which was filed under the PCT Convention on Oct. 12, 1982.